Core making machine



April 1961 G. BARRALLON 2,978,760

CORE MAKING MACHINE Filed July 11, 1958 5 Sheets-Sheet 1 ew es BARRALLONINVENTOR April 11, 1961 e. BARRALLON CORE MAKING MACHINE 5 Sheets-Sheet2 Filed July 11, 1958 I NVENTOR Gan es L A ril 11, 1961 G. BARRALLON2,978,760

CORE MAKING MACHINE Filed July 11, 1958 5 Sheets-Sheet 5 Fig.5

Geor es BARRALLUN INVENTOR April 19$1 G. BARRALLON 2,978,760

CORE MAKING MACHINE Filed July 11, 1958 5 Sheets-Sheet 4 INUENTUR sBARRALLON April 1951 G. BARRALLON 2,978,760

CORE MAKING MACHINE Filed July 11, 1958 5 Sheets-Sheet 5 Gm," BARRALLONR INVENTO CORE MAKING MACHINE Georges Barrallon, Firminy, France,assignor to Compagnie des Ateliers et Forges de la Loire, Paris, France,a corporation of France Filed July 11, 1958, Ser. No. 748,571

Claims priority, application France July '16, 1957 Claims. (Cl. 22-10)This invention relates to machines for making foundry cores and it is anobject of the invention to provide an improved automatic core makingmachine which will operate efliciently, reliably and simply to providean increased output of well-formed cores with a minimum amount ofmanpower. Another object is to provide such a machine which will beespecially well-suited for work with core compositions of the typecomprising mixtures of sand and synthetic polymerizable resins which arequickly settable by the application of heat to the core molds, or otherquick setting means. Further objects will appear as the descriptionproceeds.

The machine of the invention generally applies the conventionalcore-making method which involves discharging sand from a sandreceptacle into a core-mold or corebox, by means of a blast ofhigh-pressure air at a pressure of about 5 to 6 kg. per sq. cm.According to an object of the invention, however, improved structure isprovided whereby this conventional step is performed by fully automaticmeans in operative relationship with other steps of a completecore-making process.

According to an important aspect of the invention there is provided in acore making machine, in combination, a first turntable having a verticalaxis and supporting a circumferential array of sand receptacles, secondturntable means having a vertical axis horizontally displaced from thefirst axis and supporting a circumferential array of core-boxes, saidarrays being substantially tangent as seen on a horizontal plane anddefining a corefilling station at their point of tangency, means forsynchronously imparting steps of rotation to both turntables so assimultaneously to present a receptacle and a corebox said station with abottom outlet of the receptacle directly overlying an upper inlet of thecore-box, a sand tank, and means filling each receptacle with a chargeof sand from the tank prior to presentation of the receptacle to saidstation, air blast means positioned substantially at said station abovesaid receptacles and cooperable with each filled receptacle presented tosaid station for discharging the charge of sand thereof into saidcore-box, and means for automatically operating said turntable rotatingmeans and said air blast means in timed sequence for filling sand intothe successive core-boxes of said array.

An exemplary embodiment of the invention will now be described forpurposes of illustration but not of limitation with reference to theaccompanying drawings,where- Fig. l is a general perspective view of themachine;

Fig. 2. is a vertical axial section of the sand tank, assembly showingthe air blower units, the core-box clamping vice jaws (the core-boxsections are not shown) and the core receiver table;

Fig. 3 is a plan view of the sand tank showing the scrapers for fillingthe core-boxes and related mechanism;

Fig. 4 is a sectional elevation of the blower head;

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Fig. 5 is a plan view of the sand tank rotating means; and

Fig. 6 is a perspective view of the assembly including the clampingdevice and core-box means.

As shown in Figs. 1, 2 and 5, sand is adapted to be contained in agenerally cylindrical tank 10 having a central hub part 11 which isjournalled about a vertical shaft 12 and is rotated by a drive systemcomprising a piston 13 movable in a cylinder 13c and connected with apiston rod 13d. The rod 13d is pivoted to a pair of integrallyinter-connected spaced flanges 132. A pawl 13a pivoted to a flange 13eis engageable with the ratchet teeth of annulus 13b secured to hub 11,and the pawl is applied into engagement with the ratchet 13b by a spring13 When pressure fluid, e.g. air, is delivered into the cylinder throughinlet 13g, on the side of the cylinder through which the piston rod 13dextends, the other cylinder side being exhausted, the piston 13 isdriven to the right (Fig. 5) and pawl 13a drives ratchet 13b to impartan incremental rotation to sand tank 10 about its axis.

Supported from the under wall 10a of the sand tank and spaced at equalangular intervals around a common circumference, are a number of blowerunits or cans 14 which are each adapted to be filled with a charge ofsand during rotation of the sand tank by the action of scrapers 15secured to cross links 15a. The cross links in turn are secured to aflange connected to the cylinder 13c serving to rotate the sand tank,see Fig. 3, so that on rotation of the tank the scrapers force sand intothe blower cans 14, filling the latter.

A latch 16 engageable with sockets 17 carried at the under wall of thesand tank positively locates the tank at each of the successive angularpositions in which a blower is in operative position in relation to acore-box, as will presently be described, the latch is actuated by apiston 1611 working in a cylinder 16b having a pressure inlet 16c towhich compressed air is selectively delivered so that latch 16 will bedepressed or retracted to allow rotation of the sand tank 10 and will belifted to latching position to block rotation of the tank.

Each blower can 14 is mounted in the bottom wall 16:: of sand tank 10 soas to be vertically slidab-le therein, in such a way that its dischargeoutlet will be applied into engagement with the opening in the core-boxwhen the blower unit is urged downwards by the blower head, as will bedescribed. A spring .18 constantly biases the blower to its downward orextended position.

The system so far described constitutes a first turntable assembly whichis bodily adjustable in the vertical direction by means of a handwheel21 to enable its being adapted to varying vertical dimensions ofcore-boxes.

Arranged centrally below the sand tank is one of the pair of core-boxclamping vices 19, actuated by a com pressed-air piston 20.

A table 22 serves to receive the finished cores and is secured on acentral hub 23 rotatable about a vertical shaft 24 displacedhorizontally from shaft 12, under the action of a system 25 similar tothe system described above for rotating the sand tank. As with the sand.tank, the proper angular positions of the table are deter mined by apiston-actuated latch. Mounted on the table are core supports of asuitable shape corresponding to that of the type of cores to be made andshown in detail in Fig. 6. Each support comprises in the illustratedform, a flat plate 41 secured to the table 22, and having points 42projecting upwards from it in positions corresponding to the portions ofthe cores 43 to be made, which points serve to retain the core containedin core-box 44 in a vertical upstanding condition when the box isremoved from the core, and prevent displacement of the core relative tothe table and its dropping ofi the table on rotation of the latter. Thecore supports are arranged at regular intervals around a circumferencewhich is substantially tangent, as seen in vertical projection, to thecircumference around which the blower cans 14 are spaced.

The receiver table constitutes a second turntable assembly which isbodily adjustable vertically in accordance with the vertical size of thecore-boxes.

Disposed above the table 22 is a further clamping vice 26 which supportsthe other section of the core-box, and

which vice is actuated with a compressed-air piston 27.

Vice-actuating pistons and 27 are operated to eifect automatic openingand closure of the core-boxes in properly timed sequence. One of thesetwo pistons is provided to develop a greater force than the other andthe length of its operating stroke is adjustable so that the plane ofjunction of the core box sections will at all times be positioned inaxial alignment with the blower can M in operative position. The vices'19 and 26 are mounted at a fixed vertical elevation, one beingsupported on the shaft 24 on which the table is rotatable, and the otheron the shaft 12 on which the sand tank is rotatable.

A blower head 28 is provided for blowing sand from each 14 intoacore-box, and comprises a cylinder 29 connectable to a source ofcompressed air and itself providing a store of air under pressure. Thecylinder 29 is sealed at its lower end by a valve 30 operated by a shank31. The valve shank 31 is actuated through a rocker 32 by a piston 33.This assembly is bodily displaceable vertically up or down by means of arack 34 secured to cylinder 29 and operable by gears 34' and 35. Thegear 35 further meshes with racks 36 and 37 actuated from air pistons 38and 39.

Piston 33 when operated in its cylinder causes downward movement of theblower cylinder 29 to bring it into engagement with the sand-filledblower can 14 which has been advanced into operative position under it.The blower cans are spring mounted as already described so that, underthe pressure exerted upon the can by the blower cylinder, the nozzle ismoved down into engagement with the core-box aperture. After the blowingoperation has been efiected, piston 39 is actuated to cause thesubsequent upward movement of the blower cylinder.

The sand tank then has a further step of rotation imparted to it tobring the next blower can into operative position over a core-box formaking a further core.

The operation of the various actuating pistons in the proper timedsequence is effected by any suitable timing control means such as asystem of cams for example, acting on the various air-valves and drivenfrom a suitable source of power such as a motor and speed-variator unit49. Such timed control systems are well-known for various purposes ofautomatic control and hence do not require further description.

According to one advantageous form of the invention, the automaticoperating means may be set to provide the following sequence of steps:

(1) Opening the core-box clamping vices 19 and 26 to open a core-box andrelease a finished core;

(2) Simultaneous incremental rotation of receiver table 22 and sand tankiii and concurrent actuation of the latching means for properly locatingthe table and tank at the fresh operating position;

(3) Closure of vices 19 and 26 to clamp the core-box in place;

(4) Lowering the blower cylinder 29;

(5) Discharge of sand from the blower can into the core-box; and

(6) Return of blower cylinder to its idle upper posi tion.

Advantageously, the motor and speed variator system operating theautomatic timing systems, may be controlled through pneumatic switchingmeans, such as a .latch operated by a mercury switch, for automaticallystopping and starting the motor at the end and beginning of .eachoperating cycle.

It will be understood that in the specification and claims the word sandis used to designated any of the pulverulent compositions usable inmaking cores.

What I claim is:

1. In a machine for foundry cores, the combination comprising a firsttable rotatable about a vertical axis, a series of sand receptacleshaving lower and upper openings supported by said table along thecircumference thereof, a second table rotatable about a vertical axisoffset from the axis of said first table, a core box having an upperopening supported by said second table comprising two half boxes openingand closing in a vertical plane, a pair of camping devices locatedrespectively in general vertical alignment with said two vertical axes,each half box being fixed to one of said clamping devices, means forsynchronizing the rotation movements of said two tables, means foroperating said clamping devices for closing and opening said two halfboxes when a sand receptacle is directly above said core box therebydefining a filling station for said box when the axis of a receptacle islocated in the closing plane of said core box with a lower opening ofthe receptacle directly superposed to said upper opening of said corebox, a reservoir for sand, means for filling each receptacle with acharge of sand from said sand reservoir before said station, means forblowing air located above said receptacle and operable at the same timethat each receptacle is presented to said station for the discharge ofthe sand from the receptacle into said core box, means for operatingsaid two tables and said means for blowing air to fill with sand saidcore box at said filling station.

2. The combination claimed in claim 1, wherein said sand receptacle issupported on said first table above said receptacles and scraper meansare provided in said tank for filling sand into said receptacles onrotation of the first table.

3. The combination claimed in claim 1, wherein said means for blowingair is vertically displaceable at said filling station between an idleupper position an an operative lower position in engagement with areceptacle presented to said station.

4. The combination claimed in claim 1, wherein said receptacles aremounted for vertical sliding displacement relative to said first table,between an idle upper position and an operative lower position andwherein said lower opening of the receptacle is engageable with theupper orifice of a core-box, spring means biasing the receptacles tosaid idle position, and said air blowing means in their movement towardstheir lower active position maintaining said receptacles in engagementwith the upper opening of the core box against said spring.

5. In the combination claimed in claim 1 wherein positioning latch meansreleasably engage said tables for positively locating said tables intheir correct positions in relation to said station.

References Qited in the file of this patent UNITED STATES PATENTS819,883 Hewlett et al May 8, 1906 1,458,903 Holmquist June 12, 19231,573,436 Anderson Feb. 16, 1924 2,196,403 Thompson Apr. 9, 19402,791,012 Miller May 7, 1957 FOREIGN PATENTS 779,926 France Jan. 24,1935

